Lamp socket



May 13, 19:24. 1,493,988

T. J. KERWEN LAMP SOCKET Filed May l@ 1921 'Patented May I3, 19.241.

unirse stares racines PAENT THGMAS J. KERWIN', 0F CHICAGO, ILLINOEES, ASSIGNOR, T0 EDIUNDS ein JONES CGR- PORATION, A CORPORATION OF NEW YORK.

LAMP SOCKET.

Application lef May 16,

To all whom it may concern.'

Be it known that I, THOMAS J. KERWIN, citizen of theUnited States, residing at Chricago, Illinois, have invented certain new and useful Improvements in a Lamp Socket; yand I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to sockets for incandescent lamps, its general objects being those of providing a compact and cheaply manufactured socket which will hold the lamp firmly interlocked in spite' of jarring and which will readily adapt` itself for use with rear wiring. Furthermore, my invention aims to provide a socket of this class which will be particularly suitable for use on the instrument boards of automobiles, which can readily have its metal parts secured directly to the insulating panel of such a board, and which can conveniently be used as a cowl lamp.

In certain underlying principles, my invention is an improvement over the lamp socket disclosed in U. S. Patent No. 1,106,459, of August 11, 1914, to George C. Knaulf, which patent shows a spring interposed between the inner and outer shells of a socket and continuously tending'to slide one shell lengthwise of the other, one of the shells being equipped for interlocking with the base of the lamp while the other is fast with respect to one of the socket terminals. In the construction of this Knauif patent, the. two relatively slidable shells or casings were electrically connected to each 4other both by the spring and by a finger and slot arrangement which prevents the inner casing from rotating with respect to the outer. Consequently, such a construction only lends yitself readily to grounded circuit connections, such as those employed in automobile lighting when one terminal of the circuit is grounded through metal parts of the automobile.

These grounded circuit or single-wire circuits are now being abandoned to a consid` erable extent in automobile lighting practice in favor of a two-wire arrangement which permits al1 portions of the circuit to be insulated effectively from m'etal portions of the vehicle. My invention aims to pro- 1921. semi No. 470,160.

vide an improvement over the said Knauff socket which will readily lend itself to such a two-wlre construction, which also will be cheaper to manufacture and which can more Yrotation of the inner and outer shells, and

aims to reduce the number of fastening elements required in connection with the terminals of the socket. For this latter purpose, my invention aims to provide wire terminals each secured to the insulating base 'of the socket by a single rivet and each so arranged as to prevent it from rotating about the said rivet as an axis; it also aims to employ one of the rivets used for this purpose as the cylinder for a spring-pressed plunger affording the connection between the wire terminal and the sliding inner shell of the socket, and to provide a construction in which the assembly of the parts causes this inner shell to retain the spring-pressed plunger in operative position. Still further and more detailed objects will appear from the following specification and from the accompanying drawings, in which- Fig. 1 is a central and longitudinal section through a socket of the instrument board or cowl lamp type embodying my invention.

Fig. 2 is a horizontal section through the same taken along the correspondingly numbered line of Fig. 1 and showing the method of preventing the inner shell from rotating.

Fig. 3 is a perspective view of the wire terminal from which the electrical connection is made to the axial lamp terminal.

Fig. 4 is a section similar to a portion of Fig. l and showing another arrangement for making the electrical connections from one wire of the circuit to the inner slidably mounted socket shell.

Fig. 5 is a fragmentary section taken along the line 5-5 of Fig. 2 and showing the arrangement used for preventing the in- `ner shell or collar from rotating with respect to the -forward insulating ring.

In the embodiment'of Figs. l to 8 inclusive, the socket of my invention includes an outer shell 1 equipped at its rear end-with an outwardly directed flange 2, this shell being desirably contracted in diameter for the forward portion of length so asto,l A slidably it a hood.. or cowl 3 whi'cli'h'asa" suitable light-emitting opening and which bottoms on the junctures of the two dierently diametered shell portions when in use, after the manner shown in Fig. 1. The

* this shell by slightly indenting the shell into ing pins 29 'on the base of a socalled 'Edi.

the insulator at one or two points after the mannerl shown at 26 in the same figure.

The insulating washer 6 slidably is sleeved upon an inner shell or collar 7 which is equipped with bayonet slots 8 equipped for interlocking with the base of the lamp, as4

for example by providing bayonet slots 8 for interlocking with the laterally projectswan lamp, this being a type of lamp for which the socket of my invention is particularly suited. The collar,7 has at its rear end a number of outwardly directed 'fingers 9 supporting a lower washer 11 which is also of insulating material and which slidably fits the space between the outer shell 1 vand the inner shell or collar 7. Interposed 'wards the base of the socket. In so doing,

this Spring continuously tends to approach the bayonet slots 8 to the head 13 of a cir! cuit terminal here shown as a tubular rivet 14 extending through the insulating base 4 of the socket axially of the latter. vThis rivet 14 constitutes the fastening for the wire terminal l5 to which one wire of the circuit may readily be clamped by a binding screw 16. To prevent this wire terminal 15 from rotating about-the rivet 14 as an axis, I desirably provide it with an integral projection 17 entering a hole 28 punched in the insulating base 4, so that the engagement of the knob 17 with the wall of this perforation will prevent lateral movement of the wire terminal 15, although the .latter is only secured to the base 4'by a single rivet.

For the other wire terminal I desirably employ .a somewhat similar angle piece 18 also shown as having a knob interlocked with the insulating base, but here shown with this knob entering only a relatively shallow indentation in the base. This wire both a spri terminal 18 is fastened tothe base 4 by a' tubular rivet 19 having its lower end closed so as to form a elosed-endfcylinder housing n 20 and the lower end of a plunger 21. Ibis plunger 21 projects above the'base 4 and is continuously` pressed by the spring 20 into contact with one ofythe lingers 9 yon the rearend of the,l collar 7,

'thereby affording the electrical connection between the wire terminal 18 and the said collar or inner'shell.

To preventv the collar 7 from rotating with respect to the shell or casing 1, I desirably form a slight outward bulge or groove 22 in this collar for slidably entering la corresponding groove in the. nipper-washer-6 as shown in Fig. 2 and in 1g. 5.- ,Consequently, since this washer 6 is interlocked `against rotation withxrespect to theouter shell, the formation22 and the said groove will prevent .the collar from rotating with respect to the outer shell, thus facilitating the attaching and detaching ofthe lamp from the socket. f

`To secure 'a proper spacing betweenfthe standard spacing between the extreme tip of the lamp base and the lateral projections on this base. Consequently, when the lamp `is being inserted, 'the-tip of the base will engage the head 14 and the oblique portions of the slot 8 will serve as cams for sliding the collar 7 against the pressure of the spring 12'until-the said projections snap into the hook ends of the slots. t

While the collar 7 is thusl being moved lengthwise of the outer shell, the plunger 21 continuously maintains the electrical connection to the same and hence affords the circuit connection through the shell of the lamp base. However, the washers 6 and 11 insulate the spring from the collar 7, so that the desired insulation is maintained betweenv the two wire terminals. v

Where such a socket is to be vused as one of the features of an assembly mounted on anl insulating panel, the base 4 may constitute an integral portion of this panel; thatis to say, the various metal parts may be securedv directly to the panel instead'ot being first mounted on a support on the base. However, while I have illustrated and de scribed my invention inan embodiment including various details of construction and arrangementI do not wish to be limited to 'slot 8 and the head of the rivet 14 (which Afrom the spirit of my invention.

ample, instead of using a spring-pressed the latter, it being obvious that numerous changes might be made without departing For explunger for continuously maintaining the electricalV connection from the Wire terminal 18 to the collar or inner shell of the socket, I may employ a spring contact-finger 30 secured to the wire terminal 18 by the same rivet 31 which fastens the latter to the insulating base 4; and may have this finger in l over, both of these terminals are stationary,

thereby avoiding any strains due to movements of the wires attached to Ithe same.

I claim as my invention:

1. A lamp socket comprising an insulating base, a shell supported thereby with freedom for relative movement axially of the shell, the said shell having its axis transverse of the said base, the shell having means thereon for interlocking with the base of a lamp to hold the lamp with the end of its base adjacent to the Asaid insulating base, a wire terminal fast upon the insulatingbase and having a stationary contact portion disposed for engaging a terminal on the lamp base, means for preventing rotation of the shell with respect to the insulating base, and means carried by the insulating base for aoding a circuit connection direct to the Shel 2. A lamp socket comprising an outer shell, an insulating base fastened to the rear end of the shell, an inner shell slidably mounted in the outer shell and provided with means for interlocking with the base of a lamp, the inner shell having at its rear end a contact portion extending transversely of the shell, a wire terminal member having a contact portion disposed upon the front of the insulating base and directly engaging the lamp base, a spring interposed between the inner and outer shells to urge the inner shell rearwardly, and a second wire terminal member having a portion yieldinglyT engaging the said contact portion of the inner shell. v

3. A lamp socket comprising an outer shell having an outwardly directed flange at its rear end, an insulating base secured to the said iiange, an inner shell coaxial with the outer shell, insulating'means spacing the two shells from each other, a spring continuously tending to slide the inner shell rearwardly, a circuit terminal having a rigid 'contact portion disposed on the frontA of the insulatingbase coaxial with the said shells, the inner shell having means thereon for interlocking with the base of a lamp and vholding the lamp with the usual axial terminal thereof in engagement with the said contact portion of the circuit terminal, and a second circuit terminal having a yielding -'portion contacting continuously with the rear end of the inner shell.

4e'. A lamp socket comprising a supporting member, a lamp-contacting terminal fast thereon, a shell having means theron for interlocking with the lamp base, the said shell being slidable with respect to the supporting member, a. circuit terminal having one portion fast upon the supporting member and another portion continuously cont-acting with the said shell, spring means continuously tending to slide the shell in one directionJ and means for insulating the shellfrom metal parts of the supporting member, the said insulating means having means thereon for preventing rotation of the shell with respect to the supporting member.

5. A lamp socket comprising relatively slidable and relatively insulated inner and outer shells, the inner shell having means thereon for interlocking with thelateral projections on the base of the lamp, a Wire terminal fast with respect to the outer shell, but

insulated therefrom, said terminal having p means for contacting with the end of the lam base, and spring means opposed by the inter ocking of the lamp base with the socket, -said spring means continuously tending to slide the inner shell in one direction 4with respect to the outer shell, and means .for preventing relative rotation of the inner and outer shells.

6. In a lamp socketx in combination, a stationary annular member, a shell slidable with respect to the said member and having means thereon for interlocking with the base of a lamp, insulating means simultaneously spacing the said shell from the annular member and preventing rotation of the shell, a

spring continuously tending to slide the said shell in one direction and insulated from the annular member by the said insulating means, a circuit terminal fast with respect to the annular member and having meansfor contacting with the end of the lamp base, and a second circuit terminal associated with the said shell and affording continuous electrical connection to the latter.

7. In a 4lamp socket, in combination, a

' between the two shells and slidable with re- Y for interloclrin a second insulatlng washer disposed betweenl 2&0-y

spect to one of' the shells, a compression spring operatively interposed between the said lnsulating ring and the shell with respect to which the ring is slidable, the inner shell having means thereon for interlocking with the base of a lamp, a circuit terminal mounted on the base and' contacting with the endof the lamp base, and a second circuit terminal affording continuous electrical connection to the inner shell.

9. In a lamp socket, in combination, an insulating base,a stationary shell fast thereon, an insulating washer housed by the shell at its forward end and interlocked with the shell against rotation, an inner shell extending slidably through the insulting ring and having outwardly directed fingers at its rear end, the inner shell having means thereon Withlst'he base of a lamp,

the two shells and bearing against the said fingers, a compression spring interposed between the two insulating washers and two 4 `'conducting means carried by the insulating base and respectively affording the circuit connections to the axial lamp terminal and to the inner shell.

10.l A lamp socket comprising insulating base, an outer shell fastened at its rearv end to the said base, an insulating ring v mounted in the forward end of the shell, an inner shell slidable in the insulating ring and having means thereon forinterlocking with the base of a lamp', a second insulatin ring disposed between the two shells am slidable with respect to theoute'r shell, means on the inner'shell for limiting the movement ofthe second insulating ring with` respect thereto in one direction longitudinally of the said shell, a pair of circuit termina-l members mounted on the base and respectively arranged v for` aiording electrical connection to the inner shell and to the axial v THOMAS J. .KERWINQ 

